An Auditor Has Identified Numerous Debits to Accumulated Depreciation of Equipment.Which

An auditor has identified numerous debits to accumulated depreciation of equipment.Which of the following is most likely?

A) The estimated remaining useful lives of equipment were increased.
B) Plant assets were retired during the year.
C) The prior year's depreciation expense was erroneously understated.
D) Overhead allocations were revised at year-end.